The invention relates to a device on a spinning preparation machine, for example a draw frame, carding machine, combing machine or the like, having a drafting system for drafting at least one fibre sliver. Typically, a drafting system has drafting system rollers forming drafting roller pairs, having power transmission means for driving the drafting system rollers and having a drive motor, the drive of the drafting system rollers being effected from different sides.
In a known device (WO 91/05893 A, corresponding to U.S. Pat. No. 5,313,689; referring to FIG. 1), the drive pulleys 2, which are driven by a motor 1, are connected to a main drive shaft 40 by means of a flat belt 20 and drive pulleys 3. The rotations for the drafting system rollers 30, 31, 32 are derived from the main drive shaft 40 by way of drive pulleys 4 and 10. The drive pulley 4 is for drive purposes connected to an intermediate drive shaft 41 by means of a belt 22 and a drive pulley 5. The drafting system roller 30 is driven by the intermediate drive shaft 41 by way of drive pulleys 6 and 7 which are connected by a belt 23. By virtue of the arrangement of the drive pulleys 4, 5, 6 and 7, which have different diameters, a suitable rotational movement is to be applied to the drafting system roller 30 in dependence upon the fibre sliver to be drafted and the draft to be applied to the fibre sliver. The drafting system rollers 30, 31 effecting preliminary drafting of the fibre sliver are for drive purposes connected by means of a flat belt 24. By selection of a suitable diameter for the drive pulleys 8 and 9 it is possible to achieve a rotational speed ratio of the drafting system rollers 30, 31 relative to one another which determines the extent of the preliminary drafting of the fibre sliver. The rotational movement of the drafting system roller 32 is obtained from the main drive shaft 40 by means of the drive pulley 10 and from a flat belt 21 by means of a drive pulley 12. The drafting system roller 32 effects the main drafting of the fibre sliver. The gearing layout is expensive in terms of apparatus. The drive means has several branches and has a large number of drive elements. A particular problem is that several transmission steps are necessary, which results in gear losses and accordingly in addition reduces the efficiency of the drive means.